Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations declare destructiveHint=true, which is counterintuitive for an 'update' and would warrant explanation, yet the description says nothing. It also omits whether this is a partial patch or a full replace, whether omitted fields are cleared, and that customerId is a superadmin-only acting-on-behalf parameter. For a destructive mutation with no output schema, these gaps are material.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

A single tight sentence with the resource and mutable fields front-loaded and zero filler. It is appropriately sized for what it chooses to say, though its brevity comes at the cost of the behavioral detail noted elsewhere.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

A mutation tool with destructiveHint=true and no output schema needs to explain replace-vs-merge behavior, reversibility, and permission requirements. The description covers none of this, leaving the agent without the information needed to invoke it safely.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the schema already documents all five parameters including the superadmin-only customerId. The description names name/description/tags, adding no syntax or semantics beyond the schema, so the baseline of 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb (Update) and resource (persona) plus the affected fields and the 'existing' scoping constraint. It does not distinguish itself from the sibling create_persona/get_persona/list_personas beyond the verb, so it stops short of a 5.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

No when-to-use guidance, no prerequisites, and no mention of alternatives such as create_persona (for new personas) or get_persona (for reads). The agent must infer the entire usage boundary from the verb alone.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.